Pointwise approximation of modified conjugate functions by matrix operators of conjugate Fourier series of [Formula: see text]-periodic functions

We extend the results of Xh. Z. Krasniqi (Acta Comment. Univ. Tartu Math. 17:89-101, 2013) and the authors (Acta Comment. Univ. Tartu Math. 13:11-24, 2009; Proc. Est. Acad. Sci. 67:50-60, 2018) to the case when considered function is [Formula: see text]-periodic and the measure of approximation depends on r-differences of the entries of the considered matrices.